“…Attempts were made to contact authors from 39 studies for additional data (6,7,10,; 36 replied, providing data previously unpublished in this form from 245,455 subjects. Six authors could not provide data (47,48,57,(59)(60)(61) and one author (33) referred us to another publication, but this study was not suitable for inclusion (67). The full text was unobtainable for 3 studies (68)(69)(70).…”